Furnace



Jan. 24, 1928.

w. M. DUNCAN FUHNACE Filed Jan.9, 1924 2 Sheets-Sheet l 'l nl W y gl ATH/5.

Qian. 24, 1928 W M. DUNCAN FURNACE Filed Jaw. 1924 2 Sheets-Sheet 2 `-/5 rQ TVQ /6 y @55% www@ A WOR/vivas Patented Jan. 24, 1928'.

PATENT WILLIAM fD-UNGN, 0F ALTON, ILLINOIS.

v lEURNACE.

Application fle'fl January 9, 1924. YSerial No. 685,269.

his invention relates to improvementsv in furnaces, and more particularly to a furnace provided with heat-radiating "blocks arranged in the combustion 4chamber to form a heat-radiating arch, orignition arch.

Prior to Lthis invention it Vhas been customary 'to 'locate the arch in `an approximately horizontal position directly above the fuel,`

and a curtain wall usually extends upwardly from the inner end 'of the arclr'to 'form of 'a vertical passageway forthe hot gases passing from the rear Vof the combustion chamber to the boiler,` or other apparatus `to be heated. y

,"One ofthe objects of the present invention is to simplify the construction, andto'econ ornize in manufacture and installation thereof, by avoiding the `necessity of using the element known asa curtain wall, and at the `saine time utilizing the 'arch Vto form the front wall ofthe combustion chamber.

Another object is to increase 'the efficiency ofthe furnace by exposing va relatively large portion of the boiler to the radiant heat of the lire in the combustion chamber. Heretofore, the horizontal ignition arch has been arranged directly between a portionof the fire `and Athe boiler where it `preventstransmission of radiant heat `from thatportion of Athe "fire "to v`the boiler.' YAccording.to the present invention, `the iheatradiating arch lies'atan angle to the jgrateyand this ,angle is preferably greater than degrees, so `the arch d'oesn'ot j .prevent free transmission of radiant heat from the fire *to a boiler, or"

other apparatus, directly above the grate.

Another-*Objectis to producea heat-radiating larch which will not be rapidly worn,` away by the `abrasion of ,the material known the furnace, so as to vmove away 'fromthe face ofthe arch, and this face is notiexpesed vto the hot blast of fiameand ashes resulting 7^55 from a draft forced through the fuel.

A further object is toincrease the fuel'capacity of the furnace, i. e., to 'provide for rapid combustion vof a large Avolume of fuel in a furnace where `intense heat is des'ired.6li The ordinary arch transmits its heattothe front portion of the `fuel "bed, ltraveling grates being ,provided with such archestto aid in the ignition ofi'the ffuel which `enters the front of `the combustion chamber. "The arch .to be hereafter describedin'ay *be arranged to very effectively transmitheat to the 'rear -as `well as tothe "frontk of v`-the fuel bed, and owing to'thistransinission Aoftl-re heat, a relatively thick lbed of fuelcanlbe quickly and thoroughly "consumed on #the grate. This is especially advantageous ina furnace wherein it is desirable to obtain .a large fuel capacity on `a 'traveling grate.

In a heat-radiating arch, the blocks of `re` r75 fractory vmaterial are Asubjected 'to intense heat and Aother Vconditions which A.result in breakage ofthe bloclrs, and iiflthe archis approximately horizontal, the cracked "01' brdlren Ap arts drop freely from uthe :arc-h and 80 fall onto the fuel. Thearchherein disclosed is `preferably arrangedfat such an angle that the broken'parts will, in manyinstancesfbe retained in the arch structureuntil itfisconvenientto replace jthe broken block.

A further :object is to produce an inclined arch whereineach of :the refractoryblocks is supported independentlyofthe others, -so thatthe'loweriblocks are not subjected tothe weight of the upper blocks, and "each blockl is free 'to yexpand and contract independently of the others. TEllis tends to reduce breakf age of the blocks and itis accomplished by means of fa simple supporting device which will be hereafter described. With the foregoing 'and other "objects in viewythe invention comprises thenovel 'construction, vcombinationand arrangement of parts hereinafter more specili'ca'lly 'described and `illustrated inthe accompanyin'gdraw- 1790,

ings, wherein shown the 'preferred -enibodinient of thelinven'tion. However,1itisto be understood that the linvention comprehen'ds changes, `variations fand moditlcations which 2 come within the scope ot the claimshereunto appended. y

Fig. I is a vertical section showing portions ol a boiler ina furnace embodyingl the features of thisinvention. y y

Fig. Il is a. detail View, partly in section, showing a row oi the blocks and its support ing means. A W

Fig. Ill is an enlarged section on the line III-III in Fig. Il.

Fig. 1V is a section takenapproximately on the line 1V-IV inFig. lll, with the blocks shown in elevation.

i porting portion of the `grateherein shown is approximatelyhorizontal. A fuel hopper 5 is located above the iront portion of the grate and provided with a discharge opening 6 for the discharge oit' fuel onto the grate. The combustion chamber is provided with a bridge wall at the rear of the grate. The

tubes S :torni part et a boiler which lies above the grate. Y y

The front wallet the combustionchamber A is formed by a combined heatradiating arch and curtain wall comprising two horizontal rows of bloclrsA and A located at the rear of the fuel hopperli and separated from the grate to provide l'or the admission o fuel.

VThe upperportion of the arch isv formed by inclined blocks B (Fig. I) arranged in rows which extend` upwardly from the blocks il` to `forni the front wall oft Athe combustion chamber. Each block is made of refractory material and has a heat-radiatingiace 9 in the combustion chamber, a head 10 outside of the combustion chamber, and oppositely disposed recesses `11 (Figs. III and V) loi-nr` ing neck between the head and the body ot the block. y y

The arch support comprises pairs of supporting beams 12 (Figs. I and l1) arranged horizontally in front ol the inclined arch,`

andlhanger ribs 13 `loetween said arch and supporting beams, said hanger ribs being ar-` ranged transversely` ot said beams and inclined to` con'lormto the inclination of the arch.. `The supporting `means also includes upright suspension members ll depending from `the supporting beams 12 and having their lower ends secured to the hanger 'ribs 13, plates 15 secured to said .hanger ribs and extending between the lheads ot the adjacent blocks in the archLand pairs of horizontal rods 16 extending through said plates, said rods being arranged in the oppositely disposed recesses 11 to support the blocks, as shown most clearly in Fig. IH.

Each o' the inclined blocks B is thus rigidly suspended from a support including an inclined rib 1B, and the rigid suspension de `rice has a four-point contact preventing any pivotal, moi'einent ol the inclined block and securely supporting the block, se that one in clined block does .not rest upon ailother, and

each block is i'ree to expand and contract withoutliability of breaking or cracking the refractory material. `Each rigid suspension device with its tom-point contact comprises one `of the rigid plates 15 secured at its upper margin by means of two bolts 1T` (Fig. lll), providing two ol the contact points, and the rods 1G contactwith two points on opposite sides ol a block to form the other contact points.` The boltsl? prevent pivotal motion or downward displacement of` the plateslii, andthe rods 1G prevent displacement olt the blocks B.n The rods are arranged in pairs,

one above the other, so as to constitute upper `lll) and lower block-holding elements in contati. with two points on each inclined bloeit, thus preventing pivotal ,motion ordownward dieplacement oli' tlieblocks. y

Thehanger ribs 13 are preferably T-ba and the plates` can be coiiveniently lnilter to the legs of the T-shaped ineihbora. rods 1G are dctacliably interlocltcd with the blocks and said rods can be removed from the plates 153 to permit removal of the blocks.

`The hanger ribs 13 are extended loi wardly at their lower `ends (Fig. I) to receive hangers 1S which embrace the heads oil the lower blocks A and il', as shown in "lligs,` I, V and VI. y y

The supporting device thus consistsof few simple and inexpensive` elements coinbined with each other to securely hold .the

blocks in their inclined positions..

lttention is now directed to the inclina-t tion of the arch which forms .the rontwall of the combustion chamber and enables the curtain wall tobe dispensed with. The heatradiating lace ot the arch preferably lies at an angle of more than degrees relativi@ to so arranged that a straight line at alright angle to the heat-radiating face willextend to the rear et the grate.. Consequently the fuel onthe rear, as well as the front, ol the grate is exposed to the, intense heat radiated from the arch, and the'fnrnace has a relatively large :fuel capacity and a hivh degree` of efficiency `for the combustion ol the fuel` before it reaches the rear end of the combustion chamber.

kOwing to the inclination of the archI it` does not materially interfere with the trans- The lou

lll)

mission of radiant heat from the fire to the boiler 8 above the grate, and this is an important factor. The flame and hot'gases rising from the grate tend to pass upwardly and over the bridge Wall 7, so even though a forced draft is projected through lthe fuel bed, the arch is not exposed to the destructive scouring action of hot ashes and the like passing upwardly with the flame.

I claim: p

l. A furnace having a combustion chamber provided with a heat-radiating `arch inclined to form the front wall of said chamber, said arch comprising blocks of refractory material each having a heat-radiating face in the combustion chamber, a head outside of the combustion chamber and oppositely disposed recesses forming a neck between the head and the body of the block, supporting beams arranged horizontally in front of said inclined arch, hanger ribs between said arch and supporting beams, said hanger ribs being arranged transversely of said beams and inclined to conform to the 'inclination of said arch, upright suspension posed recesses forming a neck between the head and body of the block, supporting beams outside of said chamber, plates, suspended from said beams and extending between the heads of adjacent blocks in said arch, and pairs of horizontal rods extending through said plates, said horizontal rods {being arranged in said oppositely disposed recesses to support the inclined blocks. i y

3. A furnace having a combustion cham ber provided with a heat-radiating arch inclined to form the front wall ofsaid chamber, said arch `comprising transverse rows of blocks of refractory material each` having a heat-radiating face in the combustion chamber, a head outside of the combustion chamber and oppositely disposed res cesses forming a neck between the head and the body of the block, supporting beams arranged horizontally in front of said inclined arch, hanger ribs between said arch and supporting beams, said hanger ribs being arranged transversely ofsaid beams and inclined to conform to the inclination of said .bers being adapted to support a transverse row of blocks.

In testimony that Iclaim the foregoing I hereunto afliX my signature.

WILLIAM M. DUNCAN. 

